treated like a child

It's 2:23pm in the afternoon and my other half has only just got out of bed, since he was up half the night playing online gaming with him friends like he has done for the past yr!!

My son from a previous relationship who is 12 has been up since 4am feeling sick and bk and forth to the toilet and complianting of a headache. So my other half some downstairs and said "why haven't you sent him to school for?" He knew he was ill he not had one day off school in two whole years. Then he starts going off on one saying I should of sent him he's faking it and so on. He also turned round and said" the day I find out he's faking it to get a day of school is the day I kick him out that's from door" he's 12 for gods sake. I'm so fed up of him treating me and my son like this, he's also grounded my son for going on his phone and watching to much to!! That's wat 12 year old do!!!