Either one of two things:
1.(n.) When a person (usually overweight) can no longer fit into clothes of a particular size but continue to buy and wear clothes of said size, despite what their gut/hips might have to say about it. Typically occurs when a person refuses to accept that they've either become fat, or(in the case of an already lardy person), have gained even more weight.
2.(n, abstract) When a person who may feel a touch insecure about the size of their..."thing " buys condoms larger then they are.
This often leads to slippage.
1. Suffering from a classic case of size denial, Jack continued to wear his favorite size 30 jeans, despite the fact that his waistline bordered size 38.
(please note that this phenomenon is more prevalent in women.)
2. Luke wanted to buy condoms, but he when he found out he was "Garden Snake" size, his size denial kicked in.
So instead, he grabbed the Anaconda ones instead.