He doesn’t wanna have sex

My friend asked me to post this here for all of your opinion as she isn’t on flow.

Her and her hubby haven’t done the “deed” in a while and they are a happy couple. She said he recently mentioned he loves her but sex doesn’t appeal him anymore. They have been married for 2 years and no kids. She said she knows he loves her and isn’t cheating on her- but doesn’t understand the fact why he isn’t into sex at all. It that normal for a man to not wanna have sex? I told her “no.” But let’s hear from you.