When you're sucking, keep your fingers busy too.

 

Ideally, when I'm sucking a guy I like to have one hand gently stroking his balls, thereby stimulating the spunk in them to get ready to shoot, as I like to think - while the fingers of my other hand play around and softly massage the muscles of his shithole. If he's already relaxed and pliable around there or is already lubricated in that area I will try to insert a finger, maybe two, up him, being careful not to make him feel uncomfortable to the extent that his attention is diverted from what my lips and tongue are doing. Of course, depending on circumstances and locality, it's not always possible to do this as, for instance, you may be in a location, like at the piss-stalls of a public toilet, where it's not possible to have him naked or divested enough to achieve what you want. You just gotta adapt to the circumstances of the moment, don'tcha? 😉