To oil up with your partner, normally at night, and have intercourse in a sandy place. Likely to be a beach.
Tod: "Barb and I had a BP sandstrom last night."

Josh: "Nice but Barb and I did that in college."

Joey: "I just did it 3 minutes ago to Barb. What a Score!"
by BENITO MANIC May 18, 2011
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