He said "My dick is used to you". Meaning?

[ColHathi]

Going by the comments, you might need to provide a bit more context if you want people to agree on one answer ^^
To me it just sounds like a weird way of saying he would prefer to keep putting his dick in you over other girls.

[summiter]

Sounds like he is saying his dick has been with a lot of other girls. Use a condom every time!

[metalhead_66]

He really, really enjoys having sex with you. You two are a perfect fit (no pun intended)

[dthomas89]

It means exactly what it means.. that he kind of essentially owns you. That you belong to his dick

[reptocarl]

His dick fits your pussy

[Meropatrick]

What was he smoking when he said that?

[GoodGuyBreakingBad]

His dick is for you only

[harryxoxo]

He knows how to ride you

[simplelikeme]

He only wants you

[engel23]

You are the boss