In the comics, Spiderman and Deadpool are more like partners in crime-fighting and have a comical banter. They don't date. Their dynamic is based on mutual respect and occasional teasing.
The ages of Spiderman and Deadpool in the comics aren't fixed. Spiderman is usually around his 20s, but Deadpool's age is more flexible. It can be influenced by the writers' decisions and the demands of the plot. So, it's not straightforward to give an exact number for either of them.
Spiderman would probably be really confused at first. I mean, Deadpool is not your typical villain. He'd likely try to talk Deadpool out of whatever crazy plan he has. He'd be using his quick wit and trying to reason with Deadpool, saying things like 'This is not the right way to do things, Deadpool.'
Deadpool could use his sense of humor to break through Spiderman's dark thoughts. He might crack jokes that at first annoy Spiderman but eventually start to make him see things differently. As time goes on, Spiderman could come to appreciate Deadpool's unique way of looking at life, and they could become really close friends. They could also have deep conversations in between their crazy adventures. For example, while sitting on a rooftop after a fight, Deadpool might share some of his own experiences with pain and how he copes, which makes Spiderman feel less alone.