KLSS
Initialism describing the key elements of fellatio - Kissing, Licking, Sucking, and Swallowing. While licking and sucking are nearly always part of fellatio an inexperienced, or poorly trained, fellatrix may not understand the importance of kissing the penis as part of foreplay or that ejaculation should always happen in her mouth or throat and that she should at least attempt to swallow all of the semen.
Katie was initially reluctant to kneel for me but I took the time to teach her the importance of KLSS. Her oral skills are improving all the time. She still doesn’t enjoy swallowing but she understands that it’s required.