Hello,
Thank you for asking the query.
As you rightly said, the risk for any major health issue because of this incident is very low.
Unless there was any direct contact with blood of bodily fluids and his lips you need not be worried.Microbes are nothing new to the gastrointestinal system, so his body would just take it fine.
If you wish you can talk to your GP over phone, but in your case no immediate medical help is required. Watch out for diarrhoea or abdominal discomfort. That's all you need to do now.
Hope this helps,
Thank you,
PLease feel free to ask followp questions.