T-butyl

[Magaret]

A woman on whom [backside attack] is impossible due to bulkiness. The hindrance resulting is a case of too much [cushin for the pushin]. So named for inability of a tertiary alkyl halide to undergo the [Sn2] reaction.

[Sarah]

A person, usually a woman, who avoids [risque] sexual activities, especially those involving a backside nature. The phrase derives from the tendency of [functional] groups attached to t-butyl to avoid participating in chemical reactions due to steric [hindrance]. Often affectionately abbreviated as t-but (pronounced t-buit).