According to the search results, "baby birding" has two different meanings. One is a sexual act where a man ejaculates into another mans mouth, who then feeds it to another man like a mother bird feeding her young. The other meaning is the act of spitting pre-chewed food into someone elses mouth, which is also known as "baby bird". It is worth noting that these meanings are considered vulgar and inappropriate.

It is important to mention that "baby bird" also has a non-vulgar meaning, which refers to a young bird that has not yet learned to fly and leave the nest.