Is it expectable for an inmate to be in a relationship and have ways of meeting new people? I trust him I know he will come home to me but I can’t entertain him 24/7 and prison is a lonely place.

Don't even try to entertain him 24/7, it is impossible. Right now, he is testing you to see how far he can push you. What will you do for him? You have to set the rules and the boundaries. You need to make sure you are budgeting for YOUR life first. Inmates have a way to make the loved ones outside feel pity for them. Just remember that inmates have all day and night to think. Inmates are very creative and find all sorts of ways to meet new people... via mail, email, penpals that write into prison looking for friendship, or more.