It took Chuck twenty years to notice the trail of new brides he left behind? Really?
Its not really something he would notice for a while, if the few women he kept in contact with found their soulmates shortly after ending their relationship with him he would probably just chock it up to lucky coincidences. It only starts looking weird if he was stalking all of his former lovers and he noticed that everyone universally found the person they love.
Chuck tries to set Cam up with the guy of her dreams, and doesn't check to see if he's single?
It's amazing that Charlie manages to sleep with all of those women without getting a disease. Unless he has an economy sized box of condoms
He is shown using protection during the sex montage.
And he couldn't just keep buying condoms because...?