Hello, violet_girl. Thank you for writing today.
Try not to worry. You don't know that this person even has HIV.
This is what the CDC says about kissing and HIV.
*In extremely rare cases HIV has been transmitted by - deep, open-mouth kissing, if both partners have sores or bleeding gums and blood from the HIV-positive partner gets into the bloodstream of the HIV-negative partner. HIV is not spread through saliva.*
So, kissing alone (deep or otherwise) based on the above information, will not transmit HIV. Even under the rare circumstances mentioned, the transmission seems more of a remote possibility. You'd have to ask the CDC how many "extremely rare cases" they have documented to have come to this conclusion.
More information here: