help me out girls!

Okay so I have a little problem in the bedroom... for some reason I don't like sucking sick but I really want too in my past relationship it was a problem but with my new boyfriend not so much but I can tell me wants me too as he says things like you never suck my dick anymore...and in the 1st couple months I would for maybe a few seconds nothing more I just don't like it and I don't know why so please girls tell me how I could enjoy it more and give me some tips I really wanna please my man!