My husband wears boxer-briefs but I've heard that regular boxers are better when trying to conceive. Does it really make a difference?
A.
IF your husband has problems with his sperm, then all the life style choices need to apply--no smoking or street drugs, less drinking, less bike riding and hot tubs, less stress, etc.
Based on studies I have seen, the added heat of tighter undies probably won't put your guy into the male factor camp. However, if he had an added scenario of a lot of things stressing the swimmers, then that extra heat might put them over the edge and be a problem.
Time your intercourse for 5 cycles. Then if you aren't hitting it right, you may want to start looking into why and change underwear.