It's out of my system

[Aikuzo]

From perfect man, the playboy guy came in and say

Girl: Why are you telling me this? Are you in love w/ her
Player Guy: She meant nothing to me. Well, technically "they" meant nothing to me.
Girl: "They?"
Player Guy: Look in the bright side. It's out of my system.

Thanks in advance again! xD

[Josef]

system (noun): a set of connected things that form a complex whole, especially
1. a set of things that work together forming a complete mechanism or network (eg the state railroad system, a car's braking system)
2. a set of organs in an animal or plant with a common function (eg the respiratory system)
3. a complete animal (or human) body (eg "The police doctor found drugs in his system")

"to get something out of one's system" is used in sense 3 above, eg:
- literal, we need to get cholesterol out of our system
- figurative, get love out of our system (broken heart), get worry out of our system (anxiety) etc

In your quotation, it looks as though Player has got a girl, or feelings of love, out of his system.