Why is he avoilding me?

I know this guy went to school together .... i saw his bro in my teens and he works at my kids school .... we chatted on facebook for 3 weeks and i told him everything ... i got cancer he seemed to deal with it and quite supportive .... we met up last week got on really well .... when we started talking he said he wanted sex just sex .... and said it was unfair to just come for that .... im a little chubby and he said after leaving message me later i said ok ..... but he didnt reply i did it a few more times over the weekend still nothing ... ive told him to block me but he wont ? and he wont reply .... i told him i think he thinks im not sexually attracted to him .... and he know my ex always looks at me as a fat **** maybe somethings i said i shouldnt be he wont say nowt ..... werid have you got any answers ?