An inconspicuous term used to notify friends that you had intercourse for a long period of time. That you figuratively just "camped-out" at her "site".

(aka= was building a tree fort)
GUY1: "So what did you do last weekend?"
GUY2: "well, not much. . . just built a tree fort"
by Tomchew87 October 2, 2014
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