Is it normal that a friends husband wants to always fool around with me?

Is it normal that my straight friends husband wants me to put my cock in him? I'm in a 3 year relationship, and my friends have been married for 23 years! One day he passed a comment to me and it went from there! Although we've only given head to each other he wants me to bang him! I want to bang him as well, but we never get time long enough to do it! He's straight and never been with a man other than myself... Which I think is fuckin hott! I haven't been with a married man for a while, first timer at that! But is it normal to just want each other as sex partners and nothing else? Since both of our partners hardly ever give us sex, or do the nasty things we want them to do....