Leu v. State (Alaska Ct. App. Apr. 8), deals with this issue:
On May 23, 2008, Byron Leu was visiting his friend Kenneth Wehmeier. Leu had his eight-month-old daughter with him. The two men were drinking and “hanging out” as they often did. According to Wehmeier, he and Leu had previously been sexually involved, but that involvement had ended some five months earlier, when Leu met his girlfriend.
At some point during this visit Wehmeier made remarks that angered Leu. Wehmeier testified that Leu chased him into the kitchen and pushed him into some cabinets, causing the shelves and their contents to spill to the floor. Leu then held Wehmeier around the neck and punched him in the face several times….
The Alaska Statutes define certain crimes (e.g., assault, burglary, criminal mischief) as domestic violence crimes if they are committed by one household member against another. The term “household member” is commonly understood to refer to individuals who live together. But the Alaska Statutes define the term much more broadly to include … [“](D) adults or minors who are engaged in or who have engaged in a sexual relationship[.”] …
Wehmeier testified that during the year or so he lived next door to Leu they “used to hang out together a lot.” He said they were “both drinkers” and would “stay up pretty late, you know, watching TV or whatever, and we would end up in the same bed.” Wehmeier said that “pretty soon we were intimate, but we were more like friends. I mean, that was something that would happen every once and a while.” Wehmeier said he and Leu had not been “intimate” for about five months before the incident in this case, when Leu met his girlfriend. Wehmeier said he was jealous at first and that it took him a few months to warm up to Leu’s girlfriend. But he testified that “the friendship … was what was important to me.” On cross-examination, Wehmeier acknowledged that he had called Leu and been to his house a few times since the assault; he said he “thought we maybe could patch things up,” and that he “wanted to forgive [Leu].”
Based on this record, Leu asserts that any sexual involvement he had with Wehmeier was too casual to fall within the definition of “sexual relationship.” But when the Alaska Legislature defined “household member” to include adults “who have engaged in a sexual relationship,” it did not specify that the relationship had to be a serious one. As Leu points out, Minnesota has imposed this requirement by statute, and it has adopted a multi-factor test to determine when a romantic or sexual relationship is “significant.” The Alaska Legislature chose not to define “sexual relationship,” leaving the courts to construe the term in accordance with its ordinary meaning….
Judge Wolfe credited Wehmeier’s testimony that the two men had an ongoing friendship that, up until five months before the assault, included occasional sexual intimacy, and that this intimacy continued until Leu met his girlfriend. This is not the type of non-consensual or short-lived sexual involvement that falls outside the ordinary person’s understanding of a “sexual relationship.”
So it looks like a one-night stand (“short-lived sexual involvement”) is not, under Alaska law, a “sexual relationship” — presumably because it’s sexual but not a “relationship” — but friends-with-benefits is. Where exactly the line is drawn, of course, is impossible to tell, and perhaps in some situations near the line the law might be found to be unconstitutionally vague as applied; but in this instance, the court thought, there was clearly a “sexual relationship” present.