Welcome back to the Forum. In preparing to answer your question I reviewed several of your earlier interactions with Dr. Handsfield.  My sense is that you have several misconceptions about STIs.  First, STIs are not very common- most people do not have STIs. Secondly, STIs are not easy to transmit.  The most common STIs, gonorrhea, chlamydia, HIV are transmitted through penetrative mucosal exposure such as genital-genital or oral-genital or rectal-genital intercourse.  Other STIs such as syphilis, herpes, and HPV are transmitted through DIRECT contact with infectious lesions typically accompanied by friction and minor abrasion.  Even then most exposures to infected persons do not lead to infection.  With this as background, let me make a few comments to directly answer your question.

Recently the topic of STI transmission, particularly gonorrhea transmission has be the subject of considerable discussion by scientists, in part because of the hypothesis on the part of some Australian investigators who believe that deep ("French") kissing with saliva exchange may account for a substantial part of gonorrhea transmission among men who have sex with men.  Most other scientists, including us, are skeptical regarding this hypothesis and while gonorrhea may rarely be transmitted in this way, it appears to be rare and is not a concern.  Superficial kissing without saliva exchange is not a risk factor for STI however, just as sharing a toothbrush (as discussed on one of your earlier interactions) or drinking from a glass that someone else had used is NOT a risk for any STI.

I hope that these comments are helpful to you .  I would not worry about any risk for STI from the kiss that you have described.  EWH 

Occasionally cold sores (HSV-1) are transmitted by kissing but that is it.  If you do not kiss someone who has a cold sore, your risk is very, very low. CMV is not a concern with closed mouth kissing.

This completes this thread which will be closed shortly without further replies.  I hope that my replies have been helpful. Please don't worry. EWH