Simple, often secret, way of saying I Love You over text or chat, without being too forward

"allow it" means to just leave something alone, or don't worry about it. People in West London say this quite often.

The first 3 numbers you learned this in kindergarten I hope you looked this up as a joke

used in web forums to denote a quote that they entirely agree with 100%. the term "you took the words right of my mouth" comes to mind.

however, because they forums disable spaming by requiring people to type at least 3 characters per post... 123 comes to mind

If someone is trying to attack you you say 123 and punch them