Translation:If being sexy were a crime, you'd spend your life in jail.
I'm not sure if I communicated my point; my concern is that Duolingo could have used "su" instead of "la", but didn't, nor did it accept "If being sexy was a crime, you'd spend life in prison", which is an acceptable and grammatically correct translation in English, and follows more accurately the Spanish text.
To your example, a hispanohablante would likely say "perdí mi turno", but the Spanishdict.com entry is technically correct, if a bit stilted (according to my Spanish instructor).
In English you could say "I broke a leg." and it is as common to say "I missed a turn." The possessive pronoun is not required in English either. It is just that we tend to use the indefinite article rather than the definite article. It is subjunctive so I used "were" not "was", but "spending life in prison." is a well known expression which does not require the possessive either. Certainly, it is okay to put a possessive, but it is not wrong to omit it. We would not use "the" as is often the case from Spanish to English.
No, rspreng's dictionary entry is perfectly normal Spanish, as is Duolingo's example (well, the grammar at least. I'm not sure about the pickup line). The indirect pronoun often replaces the need for a possessive pronoun.
Sometimes neither is used. For example, in school a teacher might say, "Levanta la mano" - "Raise the hand." In English it's incorrect to speak like that, but in Spanish it's normal.
Interesting but a simple explanation. I'm sure you know that there are many words that come from Germanic and Romance Languages (For example the word renegade comes from the Spanish renegado). In this case, it's a word created in English and that has been adopted into the Spanish language!
Now I'm more puzzled--first, by the word "fuese"--as to the use of "fuera" as a verb (I thought it was an adverb meaning "outside" (when by itself) ). I am thinking that "fuese" is fue + se. . .So "were" + "itself"? (though, I am told that you shouldn't translate reflexive pronouns word-for-word in English). I can only guess that one could say "If being sexy were a crime ITSELF--".
The clitic, se, does not exist is this Duolingo Spanish sentence.
No, fuese does not equal fue + se. Both fuera and fuese are third person singular conjugations of the verb, Ser, in the subjunctive mood and the imperfect tense.
As the post by alfredo-martin already explained, these two Spanish words can be substituted for each other without restriction. There is no restriction because these two Spanish words have the same meaning and the same grammatical effects.
"If to be sexy" is not proper English.
A lot of times in Spanish the infinitive form of the verb "ser" is used where in English we would use the gerund "---ing" It just depends on the context.
In this example, the infinitive translates into the gerund - "If being sexy." It would not be proper Spanish to say "Si siendo sexy..."
This is where I went wrong too. I suppose I wanted to err on the side of literal, since once you deviate into all the different possible wordings there are just so many.
But! I still feel like "if to be [adjective] were [such and such]" IS proper or at least acceptable in english. Maybe a little pretentious-sounding or antiquated, but correct?