Hse 4 sale w/2 mtgs. Sale $ 10k shy of paying 2nd mtg. Can 2nd mtg stop sale? Or duz 2nd chase for recovery $?

We want 2 sell house and go seperate ways. We owe 1st mtg of $78k & 2nd of $92k. Advised that house will bring $170k B4 selling fees. Looks like we'd be 10-13 thou short of paying off the loans. Can the house be sold or will 2nd's lein stop the sale? If so end of question. If house can be sold and we can't pay off the second what are the 2nd mtg holder's options? The house is in both names. The 1st mtg is in both, but the second mtg is in her name alone. Other than not selling at this time our only other option is to walk away, foreclosure. Combined mtgs are near $1500 per mo. so renting the property out is not an option. Suggestions?