If you used 'though' or 'although', you would need to change the sentences somewhat: "Everybody laughed at my boss's speech even though his jokes were terrible." "The staff in my office are happy although they are working long hours." 'Though' and 'although' are subordinate conjunctions. That means they connect a dependent clause ("although they are working long hours") to an independent clause ("The staff in my office are happy"). When you use them you need to have a verb in the dependent clause for it to be complete. "Even though his terrible jokes." and "although working long hours." are not complete clauses. You need a subject ("they") and a verb ("are working").