The term lewing is not a standard or widely recognized term in English dictionaries. However, based on the context you provided, it appears to be a colloquial or informal term used to describe a sexual act involving anal penetration followed by oral contact.

To define it more clearly, lewing can be understood as:

The act of ejaculating (cumming) inside the anus during sexual intercourse, followed by orally sucking and removing the semen (sucking it out).

Please note that this is an informal term and may not be universally understood. It is always important to communicate clearly and respectfully with sexual partners about boundaries, preferences, and consent.