You maybe are used to a younger fellow in previous encounters, this could be normal for him, 42 is young for this but he maybe is getting very insecure because you are so young and probably you are after him for a good performance, you guys are just married, give him time, satisfy yourself any other way so you are not so willing to do it with him, wait until he approch you and do not make this an issue,at all if you have younger lovers in the past, get use to this, he is not going to behave like a 25 years old guy, let me tell you. But give him time, and try to perform for him and not forcing him to perform for you. Good luck, You got an older horse, you can not expect to win the Derby.

A 42 year old man is not able to get it up everytime a 23 year old woman wants it. he is old enough for your father. Hes; "no doubt" was having sex before you was born. (My suggestion:) Don't force him, chase him or beg him into having sex with you, those type acts will only makes his conditions even worst. Go to a sex store and buy yourself a good viperator, don't get the hard/plastice kind; Get the one that looks and feels like the real thing/a penis, the one that viperates. They comes in all sizes and colors, they are made up just like a penis, get the size of your choice. Please take my advice. I bought one for my woman because I needed a helping hand. She lets me use it on her and that even make it better for both of us, because of this" we end up having great sex; for it is a turn on for to get a lasting erection!

i want to know if have a big but is more important that big chest

It all depends on the man as to what turns him on the most. Some men like big butt women while other prefer big titts. For me to say which one men, (as a whole)
likes better is pure speculation and guess work. (Which one I like?) I prefers a woman with a very nice/ round rear end, not too big, but fine-- I like the breast
to be of a nice size, but not too big, a size that I can cup in two hands.
Maybe there other men out there may can give you a better understanding.

i know a of a guy who had a problem with getting it up because of his high blood pressure medication. so so medications can destroy your libido. i am a female and when i was on medication it destroyed mines.
he is married to a younger women so i feel like he has to communicate with you. try to talk to him on a relaxed day when he is in a good mood. you have to be careful of how you bring it up because some men can be offended by the subject.
if it is his medication, it is possible it can be changed.