Milking

My fwb and I recently (yesterday lmao) tried something to spice it up. I’m into bdsm (I’m a bratty sub but lately I’ve been dom and I’ve been enjoying it so I’m thinking I might be a switch) and it was his first time trying anything like that. I just tied his hands with some rope to my bed posts (think like he was dancing to ymca but stuck at the y) and he loved it. Today he texted me saying how he couldn’t stop thinking about it and how he “NEEDS to fuck [me] again” and he went on about how much he enjoyed it yesterday and we made plans to meet up in between classes (were in college) tomorrow. He said he wanted me to milk him (as in get as much cum out as possible) so I was wondering if anyone had tips for that. Ik that edging would help as well as prostate stimulation but we don’t have much time so I can’t edge him like I would want and I’m not comfortable putting my fingers in his ass (and I don’t have anal toys). Any tips are welcome!