I have been seeing someone on and off for 3/4 years now sex is awesome but I feel that's where it stops and starts once a week at his convenience

If you feel you are being used and you don't like this, you should tell him it's over and then move on.

Why buy the cow when you can get the milk for free?

You've been allowing this for 3/4 years now... why would you expect more? You control who you will and won't sleep with. If you aren't happy with the situation... put an end to it.

That is a booty call all right, remember the hookers at least get paid and a lover has feelings and relationship,. so when you go home after sex with nothing, that is what the relationship is.