Phone boyfriend 

A boy with whom you share a close emotional bond; communication is largely limited to over the phone. You text all the time but for some reason can’t or don’t meet up. May or may not ever become your real boyfriend.

From Schitt’$ Creek episode 5x05 (Housewarming)

(At Patrick’s housewarming party)
David (to Stevie; indignantly): Where’s your phone boyfriend?
Stevie (Exasperated): He’s...on my phone?

Phone boyfriend by Hey_kimy October 11, 2020

Cell Phone Boyfriend 

1) A guy who is very flattering and flirty, as long as he isn't face to face with you. Usually shy, but possibly a player. So look carefully!

2) A boy you have become friends with over text message and IM. You could talk together all night and day. But, you already have a boyfriend that you don't want to leave. So the relationship stays limited to the sweet conversations you have at a distance.

I have a crush on this guy, and we talk All the time. Every night! But I don't want to break up with Nevin to chase a crush. I guess I'll have to keep him as a cell phone boyfriend.

Cell Phone Boyfriend by LittlebitLost June 18, 2010

Pay phone Boyfriend 

A person's other half, who only stays around as they are being paid a monthly rent to stay around

girl 1: why does she look so upset?
girl 2: she couldn't keep up the payments to her pay phone boyfriend

Pay phone Boyfriend by the payee November 28, 2018