-1 By withholding information that we know would be useful to someone, we are making a judgement about their capacity to accept this information. Don't lie. Withholding information that you know will meaningfully change their understanding of reality is lying. — Greg Schmit 1 min ago

Unless you actually think she is too young for you in terms of how she acts, then I really don't understand what your concern is. It sounds like you're worried she thinks you're younger than you are. If she cared, she would have asked. Honestly, chill the f out. If you like her and she likes you, this isn't an issue. — Edmund Reed 48 secs ago

See added comment in answer, as well — Stilez 1 min ago

+1, thank you for offering an answer that does not berate OP or tell him that there is no solution. — AnoE 38 secs ago

+1 .. I liked really how you described the situation and I think you understood exactly the problem — Moslem Ch 18 secs ago

If she already decided she likes you there is no way you can tell her that. You can try to, but you won't get through. — mathreadler 45 secs ago

Just tell her that you want and need at least two women to be happy. — dgrat 1 min ago

@T.E.D. emotional affair is the correct term for what's going on. While I agree with your sentiment, it won't help the op to frame it that way — user19312 55 secs ago

I mostly agree with what you said first, and I would emphasize on one thing : When OP give 1 to K, he has give 1.5 to his wife. But above all, don't treat them equally that would be the worst he can do. Let's imagine his wife finds out he's been counting every thing he do with K and give the same to her it would be a disaster. — YCN- 1 min ago

While I don't disagree with this advice, none of it seems to be backed up in any meaningful way. Please tell us why you think this approach would work, and what experience or knowledge you are basing it on. — BlackThorn 1 min ago

@BlackThorn Looks to me like that's in this sentence: "You need to put at least that much effort into building (or repairing) the intimacy in your marriage, so your wife (and you) can feel equally close and satisfied with your marital relationship" I think 1006a is trying to tell OP that it's fine to build a close friendship, but he can't let that friendship become stronger than his marriage, which is what his wife is scared of. I agree with you that this answer may benefit from explicitly stating this (perhaps as a conclusion). — scohe001 1 min ago

@mattdm she was the line — user19312 32 secs ago

What kind of "emotional lines" are you talking about? Why do you need "boundaries"? If your boyfriend likes you, cares about you, and has even an ounce of character, he will stick around with you and will not betray your trust. It sounds like you want to eliminate potential "competitors" but really you're just going to limit your boyfriend's social support network. Relying solely on your partner for emotional support is not healthy so don't make your boyfriend do that. I think you're being jealous and should work on that rather than try to control your boyfriend. — 2rs2ts 20 secs ago

I know both people who a) have never felt jealousy and also people who b) used to feel jealousy, then after a lot of pain, self-reflection, and self work, managed to get over it (for example, because they wanted to engage in poly relationships and jealousy was getting in the way). As a member of class a), you are almost certainly not qualified to advise people on how to get over jealousy. You are like a colorblind person saying, why don't you just ignore the distinction between red and green, I know how easy it is! — jbch 39 secs ago

@Beofett. I agree. — VIRTUAL-VOID 34 secs ago

This answer is good and I've upvoted it, but I would suggest that you may be minimizing sexual behavior a little bit too much. I completely agree that sex is not some singular line between cheating and not, and I completely agree that you can't ignore all the other emotional factors in a marriage. But the reason that sex is so important is that it is not merely physical; it is extremely emotional. It is quite probably the most intimate act, both physically and emotionally, two can people can engage in. That's why it gets so much attention and why adultery is so devastating. — jpmc26 1 min ago

Great approach, set a clear expectation. I'd even go as far as writing down the agreement the three sisters come to and having all parties sign it. If the younger sister tries to push back at the end of her stay, it can be helpful to pull out the paper and show her she made this agreement and must stick to it. — cheshire 45 secs ago

@jpmc26 - I disagree on that assessment, but that is a different discussion for another time. — Tom 1 min ago

This is genuinely hilarious :D — Davor just now