Specifications such as 15 x 4.5 refer - in a sexual context - to penis dimensions.
Particularly when chatting, but also in "normal everyday life", many gays love to give their potential partners - more or less discreetly - information about their own Tail to transmit. Above all, the length of the same always plays an important role in this context. But: of course, a Penis not only be considered "stately" if it comes up with a length "L" or more.
The diameter can also be particularly important for the fun factor during sex. In order to convey as much information as quickly as possible, it is a good idea to use familiar abbreviations.
15 x 4.5 in this context means, for example, that the "good piece" is 15 cm long in total and has a diameter of 4.5 cm. As a rule, these data refer to the dimensions in the non-erect state. A penis of this kind could definitely be worth seeing and is certainly a welcome motif for dick pics.
The formula used here is always the same. The number before the "x" indicates the length and the number after the "x" indicates the diameter.
However, even though a long, thick penis is quite horny it is all the more important to remain honest during sex chat before a real date. It's no use for anyone to write about their cock in 15 x 4.5 if they can't even begin to fulfil the expectations that have been built up. What's more, horny sex requires more than just a "big part".