To bridge the gap, bridging the gap in its gerund form, is to pull your dick out of the ass at the end of anal sex and to spray your cum from cheek to cheek, "bridging the gap" of the anal sphincter.
I was fucking the crap out of her ass last night but I wanted a full on porno money shot, so I pull out and bridge the gap with my pearly white cum.
To lay ones forearm across the two heat sensors on a B&M coaster control panel, which forms a "bridge". This allows the operator to have one hand free during dispatch.