Boyfriend cheated on me. had sex with another girl with condom. and then unprotected oral. then he came home and we had unprotected oral sex. what are the chances he contracted hiv?

Little or no HIV risk. Infection is rare in most females, even the most sexually active; condoms work; and HIV is rarely if ever transmitted by oral sex. But there are risks of other STDs like gonorrhea, herpes, and syphilis. Play it safe and get tested. No need for HIV testing. OTOH, this lifestyle suggests possible HIV risk apart from this event, so HIV testing still should be included.