To: I think my wife is having s** with her brothers.
Me: you have to be very careful how you approach this. If what you think is true, then you need to sit down with her and carefully broach the subject with her, understanding her feelings and not being critical of whatever she might, or might not be doing with them.
I understand where you are coming from, but if she has to make a choice between them or you, which way do you think she will jump and if you lose her altogether, was it worth it, at days end.
Better to find out what she has been doing and do those things with her as well, as well as any other k**** things which turn you on, like a*** s**, if you have never tried it (use plenty of lubricant and take it slowly) I assure you it is awesome – feelings wise.
Was me, assume the worst and make allowances for that and have her perform for you much more than she is currently doing and perhaps, when her brothers have wives, see if you can f*** their wives too, after all, how can they complain, if you are later found out?