Would He Be Wrong to Demand Child Support From His Kid’s Mother for the 4 Years She Was Absent?

This story is… something and he hasn’t even considered the worst part of it.

WIBTA for saying my kids mother should pay the child support for the four years she was absent?

So I [20M] am a single father to a 4 year old. It’s a long story, but basically at the end of secondary school I started a fwb type thing with this girl I knew who was a couple of years older [she’s now 23F]. You know how these things go, dumb kids messing about, don’t take proper precautions, she ends up pregnant. She insisted she wanted to keep the baby and was excited throughout the pregnancy. When our kid was a month old, however, she dropped him off for a weekend with me then was a no show for pick up on Monday and was unreachable until late in the night, when she informed me she’d moved to the other side of the country for university and wouldn’t be coming back. She then proceeded to block any possible contact I had with her and cut me out of her life completely.

Obviously things weren’t easy for me. My parents didn’t want a baby in the house and kicked us out. I had to put my own education and career paths on hold. I’ve consistently struggled to make ends meet and we’re really just now getting to a place where we’re comfortable/have disposable income. My kids mum has just graduated from university and wants to be involved in our lives again. I’m apprehensive. For one, I can’t shake the feeling that if she could abandon our kid before, she could do it again. And two, I’m a little put out that she’s been completely no contact and uninvolved – including not paying child support – for his entire life, and now thinks she can breeze back in because it’s convenient now. I won’t stop her from seeing him, but WIBTA if I asked her to pay for all the missed child support payments?